PPT97: How to Control the Dimensions of Bitmaps (166330)

SUMMARY

When you save a PowerPoint slide in CompuServe Graphics Interchange Format (.gif), JPEG File Interchange Format (.jpg), or Portable Network Graphics (.png) format, PowerPoint calculates the size of the graphic in pixels by multiplying the slide dimensions (in inches) by 96. If you need to control the pixel dimensions of bitmap graphics created by PowerPoint, you can change the size of your slides.

Occasionally, you may want to create a graphic that is a certain number of pixels by a certain number of pixels in size, such as in the following examples:

You are using PowerPoint to create a picture to be used as the wallpaper picture for your computer and you want the picture to fill your screen exactly.
You want to output your PowerPoint slides as 35 mm photographic slides and you do not have a Windows printer driver for your film recorder. Many film recorders include software that allows you to convert Tagged Image File Format (.tif), Targa (.tga), or Macintosh PICT (.pct) formatted bitmap graphics into 35 mm slides.
You are using PowerPoint to create images that will be combined with digital video footage in a video editing program such as Adobe Premiere. Video editing programs can often combine .jpg, Device- Independent Bitmaps (.dib), .tga, or .pct formatted images with video footage.

NOTE: Although PowerPoint can only save files as .gif, .jpg, or .png bitmap files, you can use Microsoft Photo Editor, which ships with PowerPoint 97 and Office 97, to convert these to .tif or .tga files.

MORE INFORMATION

Bitmap graphics are computer graphics which are basically a rectangular array of dots of different colors. Each dot is called a 'picture cell' or 'pixel.'

Although you can import bitmap graphics into PowerPoint, PowerPoint slides themselves are not bitmaps; they are vector-based graphics. A vector-based graphic is not made up of pixels; it is made up of mathematical expressions to describe all the shapes it contains. You can enlarge or reduce a vector-based graphic without losing any details. When you export a slide as a .gif, .png, or .jpg file, PowerPoint converts the vector-based graphics into bitmaps.

To change the size of your slides, follow these steps:

On the File menu, click Page Setup.
In the Width and Height boxes, type the measurements you want.
Click OK.

The following table lists the dimensions for some commonly-used bitmap formats.

Dimensions           Used For                  Slide        Slide
(in pixels)                                    Height       Width
                                               (inches)     (inches)
-----------------------------------------------------------------
640 x 480            VGA Windows Wallpaper      5.00         6.67
800 x 600            SVGA Windows Wallpaper     6.25         8.33
1024 x 768           SVGA Windows Wallpaper     8.00        10.67
736 x 486            NSTC Video (Television)    5.06         7.67
2048 x 1366          Film Recorder (2K lines)  14.23        21.33
4096 x 2732          Film Recorder (4K lines)  28.46        42.67